Huels Aktiengesellschaft

Degussa Aktiengesellschaft

Borealis A/s

Huels Atiengesellschaft

Udo Jegelka

Manfred Kaufhold

Wolfgang Kleemiss

Guenter Kreilkamp

Annika Smedberg

Marcel Feld

Thomas Hjertberg

Bill Gustafsson

Josef Metz

Clemens Osterholt

Gerhard Thelen

Michael Korell

Jochen Kirchhoff

Stefan Frentzen

Gerhard Bachstaedter

Johan Linner

Bruno Klotz-Berendes

The present invention relates to a stabilizing agent for polymers or copolymers which is a copolymer of ethylene or propylene (A) and a vinyl compound (B) having the formula:

Stabilizing agent

Enantiomerically enriched malonic acid monoesters substituted by a tertiary hydrocarbon radical, and their preparation

A process for purifying at least 90% pure n-butyl chloride which is present in a mixture with other C.sub.1 to C.sub.4 alkyl chlorides, C.sub.1 to C.sub.4 alcohols, esters, ketones, nitrites, and organic sulfur compounds. In this process the mixture is first distilled, with high-boilers being separated off, and then washed in a plurality of stages with water and with dilute alkali metal hydroxide solution, and, optionally, an aqueous solution of H.sub.2 O.sub.2. In this manner, even a typical impurities may be separated off and a &gt;99% pure product may be obtained.

Process for purifying n-butyl chloride

The invention relates to a process for preparing 1,2,3,6-tetrahydro-2,2,6,6-tetramethylpyridine from 4-hydroxy-2,2,6,6-tetramethylpiperidine in which 4-hydroxy-2,2,6,6-tetramethylpiperidine is dehydrated at elevated temperature in the gas phase over a solid acid catalyst.

Process for preparing 1,2,3,6-tetrahydro-2,2,6,6-tetramethylpyridine

Cyclopropyl alkyl ketones are separated from 3-acyltetrahydrofuran-2-ones by adding an alcohol, water or a water/alcohol mixture to a reaction product containing C.sub.1-4 -alkyl cyclopropyl ketone and 4,5-dihydro-2-alkylfuran by-product and an acid catalyst and reacting the by-product with the added alcohol, water of water/alcohol mixture before, during or after distilling said reaction product; and effectively separating C.sub.1 -.sub.4 -alkyl cyclopropyl ketone from reaction by-products. In the preparation of cyclopropyl alkyl ketones from 3-acyltetrahydrofuran-2-ones very reactive 4,5-dihydro-2-alkylfurans are also produced. By reacting such compounds with nucleophilic compounds, such as alcohols or water, before, during or after distillation of the reaction products, it is possible reliably to separate off the 4,5-dihydro-2-alkylfurans as high-boiling addition compounds. The offgas which is produced in the production process for cyclopropyl alkyl ketones can be simply and reliably purified by reactive washing. The byproducts, which are difficult to handle for a production process, can thus be reliably eliminated.

Process for the preparation of cyclopropyl alkyl ketones

N-monosubstituted 4-aminopiperidine is prepared by a process comprising, in a single stage, continuously passing a 4-oxopiperidine and a primary amine over a metal hydrogenation catalyst under a hydrogen partial pressure of 1-500 bar at a LHSV of up to 1 hr.sup.-1.

Continuous process for preparing 4-aminopiperidines

A process for the continuous preparation of 4-amino-2,2,6,6-tetramethylpiperidine (TAD), comprising: passing triacetoneamine, ammonia and hydrogen over a catalyst of at least two layers in a reactor, wherein at least one catalyst layer comprises at least one element of the 4th, 5th, or 6th row of the 8th transition group of the Periodic Table or combinations of these metal elements on a suitable support, where the catalyst content with respect to each individual catalytically active element changes independently from the reactor inlet to the reactor outlet.

Continuous process for the preparation of

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Recklinghausen, Germany

Udo Jegelka